Among the several hypotheses on selective advantage of seed dispersal, the directed dispersal hypothesis explains the advantage of non-random seed transportation by animals to particular patch type suitable for offspring establishment. We tested this hypothesis in dispersal of a large-seeded, rodent-dispersed tree (Aesculus turbinata) in a temperate forest. We investigated the change in location of seeds through secondary dispersal, and the survival and growth of seedlings at their destinations. Hemispherical photographs taken at the seed locations both before and after secondary dispersal were used to evaluate the consequence of dispersal. Survival and growth rates of seedlings were measured to evaluate the responses of seedlings to light, the most important factor for seedling establishment in A. turbinata. Survival and growth rates of the seedlings were both positively correlated with light conditions, indicating the advantage of dispersal to the microsites with more light available. However, light levels at seed destinations were not significantly different from those at the locations of seeds before secondary dispersal nor those of the surrounding background forest floor. Survival of newly-emerged seedlings varied as a function of light level but not seedling density. This suggests that the effect of density-dependent mortality was small relative to light-dependent mortality during the seedling stage. Therefore we conclude that the directed dispersal hypothesis for this species is rejected, and that the role of rodents in dispersing large seeds secondarily is more important for finding suitable sites merely by enlarging seed shadow (mean dispersal distance = 12.2–44.7 m during the 3 years studied, max. = 41.5–114.5 m) and relatively less important for escaping natural enemies.
Plant Ecology – Springer Journals
Published: Oct 19, 2004
It’s your single place to instantly
discover and read the research
that matters to you.
Enjoy affordable access to
over 18 million articles from more than
15,000 peer-reviewed journals.
All for just $49/month
Query the DeepDyve database, plus search all of PubMed and Google Scholar seamlessly
Save any article or search result from DeepDyve, PubMed, and Google Scholar... all in one place.
Get unlimited, online access to over 18 million full-text articles from more than 15,000 scientific journals.
Read from thousands of the leading scholarly journals from SpringerNature, Elsevier, Wiley-Blackwell, Oxford University Press and more.
All the latest content is available, no embargo periods.
“Hi guys, I cannot tell you how much I love this resource. Incredible. I really believe you've hit the nail on the head with this site in regards to solving the research-purchase issue.”Daniel C.
“Whoa! It’s like Spotify but for academic articles.”@Phil_Robichaud
“I must say, @deepdyve is a fabulous solution to the independent researcher's problem of #access to #information.”@deepthiw
“My last article couldn't be possible without the platform @deepdyve that makes journal papers cheaper.”@JoseServera